Cell/Organelles Flashcards
In the human body, flagella are only present where?
Spermatozoa
Flagella and cilia have similar basic structure and resemble centrioles, how do they differ?
They all have 9 sets of microtubules arranged in a cylinder but the cilia and flagella have doublets rather than triplets of microtubules.
What is at the base of the cylinders of the cilia and flagella?
Basal body - help anchor to cell
How do prokaryotic and eukaryotic flagella differ?
Prokaryotic flagella are much thinner and lack the 9 +2 arrangement of microtubules
How do cilia move?
In coordinated waves by the contraction of the tubular proteins contained within them
What is the hereditary syndrome characterized by recurrent respiratory tract infections due to a defect in the action of the cilia
Kartageners syndrome
The inactive X chromosome in a female cell is called the _____ which is an example of _______
Barr body
heterochromatin (highly condensed and transcriptionally inactive form of DNA)
In an amniocentesis, what is the basis of the sex determination?
The presence of barr bodies (possible at 8 weeks)
Name for the extended and transcriptionally active form of DNA
Euchromatin
Why does one X chromosome become a Barr body?
After the 8th week of development, only one X is needed so the other is inactivated and becomes a dense chromatin mass called a Barr body. (only seen in males with Kleinfelters)
Females have 45 active chromosomes and 1 inactive Barr body
In which cellular component are glycoproteins (can be exported or made into lysosomes for the cells own use) assembled for extracellular use?
Golgi apparatus
What are the 2 functions of the golgi apparatus?
- Modification of lipids and proteins
2. Storage and packaging of materials that will be exported
Where does O-linked and N-linked glycosylation occur?
N-linked -> ER
O-linked -> Golgi
Which ends of the golgi receive and which send for export?
The convex cis face receives and the concave trans face is oriented to the cell membrane for transport
_____ filaments aggregate in the cisternae of the golgi. It is formed in the lumen of the ____ by binding sugars with the _____ that were previously polymerized on the _______.
Procollagen
ER
AA
Ribosomes
What is the specific protein that coats the vesicles derived from the RER which targets them for fusion with the golgi?
COP II
_____ is the core scaffold of the eukaryotic cilia and flagella, which are projections from the cell made up of microtubules.
Axoneme ( serves are the “skeleton” of these organelles)
What are the motor complexes that allow the axoneme to bend and are anchored to the microtubules?
Dynein arms
In cillia and flagella, the interactions between the ciliary _____ _____ and outer doublet microtubules generates force by sliding the doublets parallel to each other, which bends the cilium and enables it to beat.
Dynein proteins
The ____ ____, a protein complex important in regulating the motion of the axoneme, is also housed in the anxoneme; it projects from each set of outer doublets towards the central microtubules.
Radial spoke
____ is a proteinous inter-doublet linkage that prevents microtubules in the outer layer of axonemes from movement with respect to each other
Nexin
Inside a cilium, the nine outer doublet tubules are made of ____, whereas arms composed of dynein occur every __ nm down the length of the cilium and interact with adjacent doublets as a “ _____ ____” to produce bending. Links composed of another protein ____ are more widely spaced, every ___ nm and hold the microtubules in place. Radial spokes extend from each of the 9 outer doublets toward a central pair of tubules at __ nm intervals, and the cental sheath projections are present every __ nm.
Tubulin 24nm Molecular motor Nexin 86nm 29nm 14nm
Name 2 double membraned structures
- Micochondria
2. Nucleus
Name 3 non membranous structures
- Ribosomes
- Cytoskeleton
- Nucleolus
